Cytotoxicity assays are tests used to evaluate the degree to which a substance can damage cells. These assays measure the ability of compounds to cause cell damage or death, which can occur through various mechanisms such as necrosis, apoptosis, autophagy, or inhibition of cell proliferation. They are crucial in research and drug discovery for screening toxic compounds and evaluating the effects of a compound on cell health.

There are several types of cytotoxicity assays, including:

• Enzymatic assays like Lactate dehydrogenase (LDH) and glucose 6-phosphate dehydrogenase (G6PD) release assays, which detect enzymes released into the cell culture medium from damaged cells.
• Viability assays that measure cell health through membrane integrity, enzyme activity, or metabolic activity.
• Apoptosis assays for detecting programmed cell death.
• Autophagy assays which are used to identify the degradation and recycling of cellular components.

Each type of assay provides valuable information about how cells respond to internal or external stimuli, such as drugs or toxicants, and are used to determine the potential effects of chemicals on cells.